Infinite scroll stopped working.

My site is https://www.viintage.com and I’ve been using the same settings for over a year without problems. Recently I realized that the Infinite scroll on my site was only loading the first 2 pages and failing to load beyond that. If you visit my site you’ll notice that after you scroll to the bottom of the page the next images will auto load once, and that’s it. There are about 500 images that used to load on that page. Perhaps this is due to upgrading to the latest version of WordPress but I’m not sure. I have been researching this issue for about a week and haven’t been able to find anything that relates to solving this issue. Unfortunately the developer of my theme https://www.spadeinvaders.com is no longer in business especially since I paid $50 for the theme.

I have tried all major browsers and Safari and IE are the ONLY browsers that still browse my site properly. Firefox and Chrome do not.

Any help or advice would be greatly appreciated.
Thanks in advance!
-Matt